Atlas Copco rd20 in the permian Basin

The Atlas Copco RD20 and other equipment with Butch’s Rathole
The Atlas Copco rd20 drilling rig was
first introduced to the market in 1986.
It was originally designed for drilling
shallow oil and gas, as well as coal bed
methane (CBM). Since its introduction
to the market, approximately 250 RD20s
have been built and shipped all over the
world. The RD20, smaller and more mobile
than conventional rigs, is often used
to cheaply and efficiently complete the
pre-set work.
Butch’s Rat Hole and Anchor Service
is currently using the Atlas Copco RD-20
drilling rig to do the pre-set work ahead
of conventional rigs in Odessa, Texas.
This pre-set work, which is also referred
to as “top-hole work” consists of drilling
and setting surface casing ahead of
deeper drilling rigs that come in to get the
well to total depth.
Hiring companies like Butch’s to do this
type of work can save time and money,
allowing conventional rigs to move on
location, nipple-up and go straight into
drilling the intermediate and production
sections.
On August 25 th, Driller Bob Morris and
his crew drilled six 12 ¼ inch (31.12 centimeters)
surface holes, ranging from
depths of 350 to 650 feet (106.7 to 198 meters),
and set 9 5 / 8 inch (24.45 centimeter)
surface casing. Using down-the-hole hammer (DTH or DHD) drilling
methods, the crew was able to more quickly and efficiently drill through
the naturally tough subsurface formations of West Texas.
DTH drilling, also known as “percussion drilling” uses air compressors
to provide a sufficient pressure and volume of air to operate the
hammer and clean the hole. Compressed air flows down the drill string
said, “The QL120 hammered all the way
to TD [total depth] at 380 feet (116 meters).”
Monday morning, Butch’s held up
their side of the deal and handed Erickson
a check for the RD20.
The red bed is a reddish-colored, claylike
shale stratum, roughly 200 to 1,400
feet (61 to 427 meters) from surface, in the
West Texas Permian Basin oil field. Drillers
currently use PDC or tricone bits, drilling
with mud to raise the cuttings. To drill
using air on the first hole, Erickson injected
35 gpm (2.2 l/s) of water, foam and polymer
to lift the cuttings. Once drilled, casing was
installed immediately because the red bed
will swell, making it difficult or impossible
to install casing.
Smart Air power
To have enough air, Butch’s purchased an
auxiliary compressor to increase air availability.
They chose the new Atlas Copco
DrillAir XRVO 1550 CD7. This open skid
deep hole driller – 2 / 2010
where it provides power to the percussion
hammer and cleans the hole of the
cuttings. In the right application, this
drilling technique provides a faster rate
of penetration, maintains a straighter
hole, and eliminates the environmental
impact of drilling fluids.
Though most drillers in the industry
would be surprised by the aforementioned
numbers, Morris’ crew attributes
their progress to the sophisticated equipment
they’ve been using.
The Atlas Copco 1550 skid-mounted
compressor, which is the largest single
engine compressor on the market, performs
1500 CFM @ 365 PSI, or 2800 CFM
with two compressors. Morris describes
the efficiency and reliability of the product,
adding “It’s nice to have a piece of
equipment that you can turn on and walk
away from.”
Another accessory used by Morris’
crew is the Hydrocyclone hammer feature.
Designed and patented by Atlas
Copco, the Hydrocyclone improves performance
by eliminating injected water
before it gets to the hammer, yet still allowing
for water mist to clean the hole.
The hole is cleared of excess water and
therefore increases the rate of penetration
as fluids are injected.
Morris explained that each hole took about an hour and a half to
drill, adding “it took longer to set the casing that it did to drill the hole.”
Morris’ crew used threaded and coupled casing. Using T&C casing,
the crew was able to save time and eliminate some of the problems
that may be present with welded end casing, such as cracked welds
and misalignments.
At the controls is Bob Morris with D.C. Carter at left and B.J. Crawford holding the rope.
5